<p><a href="https://excalidraw.com/">Excalidraw</a> is the technology behind
  the&nbsp;<a href="#root/_help_grjYqerjn243">Canvas</a>&nbsp;notes. The
  source code of the library is available on <a href="https://github.com/excalidraw/excalidraw">GitHub</a>.</p>
<p>We are using an unmodified version of it, so it shares the same <a href="https://github.com/excalidraw/excalidraw/issues">issues</a> as
  the original.</p>